JflumtA 


JERARY 
G 


713 


U.  S.  DEPARTMENT   OF   AGRICULTURE, 

OFFICE  OF  EXPERIMENT  STATIONS, 
A.  C.  TRUE,  Director. 


INVESTIGATIONS 


ON  THE 


NUTRITION  OF  MAN 


IN   THE 


UNITED  STATES. 


BY 


C.  F.  LANGWORTHY,  PH.  D.,  AND  R.  D.  M1LNER,  PH.  B., 

Of  the  Office  of  Experiment  Stations. 


WASHINGTON: 

GOVERNMENT     PRINTING     OFFICE. 
1904. 


LIST  OF  PUBLICATIONS  OF  THE  OFFICE  OF  EXPERIMENT  STATIONS  ON 
THE  FOOD  AND  NUTRITION  OF  MAN. 


»Ch,m., 


W.  o.  Atwator.     (Four  chart,,  26  by  40  inches.,     Wee  per 


"L  1''n!Ii!".i0nS  °n  "le  chemI-*>-  «n<l  Economy  of  Food.    By  W.  O. 


('  '<  American 


B5?1^fPif^?^®^^?^^"Ste^'^1^<W^r    Bv  W.H.Jordan     Pp  57     Price  5ce 

J.   Dietary  Studies  with  Reference  to  the  Food  of  the  Negro  in  Alabama  in  1895  and  18%       ''  ,n 

ciTuml'and  MoH001^1'1!  Pn^f  th^  Tu«kve^  Normal  and  Industrial  Institute  and  the  A$8 

Pp.S     Price  5  c  cmt"Cf    College  of  Alabama.   Reported  by  W.  O.  Atwater  and  C.  D.  Woods. 

Bui.  40.  Dietary  Studies'  in  NewMexico  in  1895.    By  A.  Goss.    Pp.  23.    Price  5  cents 

-iatoesana 


Bui.  52.   NutTition   Investigations  'in  Pittsburg,  Pa.,    1894-1896.    By  Isabel  Bevier.     Pp.48.     Price, 
Bui.  53.  Nutrition*  g^stigations  at  the  University  of  Tennessee  in  1896  and  1897.    By  C.  E.  Wait. 

*  Bill  54    Nutrition  Investigations  in  New  Mexico  in  1897.   Bv  A.  Goss     Pp   20     Price   5  certs 

Dietary  Stiadies  in  Chicago  in   1895  and   1896.    Gohducted  withVe  coopStkon  of  Jan, 
BranT  P     76     Pri  °  H°USe>    Reported  ^'  W'  °-  Atwater  and  A.  P. 


Bryant.    Pp.76.     Price,  5 cents. 
Bui.  56.  H^ry^P^nt^jtoof_In^<^onin€Xito^  in  the  Public  Schools  of  New  York 

Pp  70     I?rS   5  cents1"8'  ^        Hogan,  with  an   introduction  by  A.  C.  True,-  Ph.JX 

Bui.  03.   Description  of  a  New  Respiration  Calorimeter  and  Experiments  on  the  Conservation  of  Energy 
*K  i   r«     in  the  Human  Body.    By  W.  O.  Atwater  and  E.  B.  Rosa.    Pp.94.    Price    10  cents 

Jfollet  ySp  ^    PriS0!0*  Creattn  and  Creatinin  and  their  Valuc  a's  Nutrients.'   By  J.  w. 
Bui.  67.   Stu^ie^on  Bread  and  Bread  Making.    By  Harry  Snyder  and  L.  A.  Voorhees.    Pp.51.     Price, 

pul;  *  x?£riptn$  ni-ssrw  b^i^sais  nnfl  Thdr  Nutrmv" **  *>*** 

Experiments  on  the  Metabolism  of  Matter  and  Energy  in  the  Human  Body     Bv  W    O 
Price  10  cents'  &>  BeuedlCt>  with  thc  co°Peration  of  A.  W.  Smith  and  A.  P.  Bryant.  '  pp.  112! 

Bui.  71.   Dietary  Studies  of  Negroes  in  Eastern  Virginia  in  1897  and  1898.     Bv  H.  B.  Frissell  ami  Isabel 
Bevier.    Pp.  45.     Price,  5  cents. 

Price   fcehts   °f  University  Boat  Crews-     BJr  W.  O.  Atwater  and  A.  P.  Bryant.     Pp.  72. 

Bui.  84.   Nutrition  Investigations  at  the  California  Agricultural  Experiment  Station,  18%-ls'is     KV 
M.  h.  JalTa.     Pp.39.     Price,  5  eents 


Bui.  85.    A     .    f . 

[Continued  on  third  page  of  CDVIT.  1 


U.  S.  DEPARTMENT   OF   AGRICULTURE, 

OFFICE  OF  EXPERIMENT  STATIONS, 
A.  C.  TRUE,   Director. 


INVESTIGATIONS 


ON  THE 


NUTRITION  OF  MAN 


IN  THE 


UNITED  STATES. 


BY 


C.  F.  LANGWORTHY,  PH.  D.,  AND  R.  D.  MILNER,  PH.  B., 

Of  the  Office  of  Experiment  Stations. 


WASHINGTON: 

GOVERNMENT     PRINTING     OFFICE. 

1904. 


OFFICE  OF  EXPERIMENT  STATIONS. 

A.  C.  TRUE,  Ph.  D.,  Director. 

E.  W.  ALLEN,  Ph.  D.,  Assistant  Director  and  Editor  of  Experiment  Station  Record. 
C.  F.  LANGWORTHY,  Ph.  D.,  Editor  and  Expert  on  Foods  and  Animal  Production. 

NUTRITION    INVESTIGATIONS. 

W.  O.  ATWATER,  Ph.  D.,  Chief  of  Nutrition  Investigations,  Middletown,  Conn. 
C.  D.  WOODS,  B.  8.,  Special  Agent  at  Orono,  Me. 

F.  G.  BENEDICT,  Ph.  D.,  Physiological  Chemist,  Middletown,  Conn. 
R.  D.  MILNER,  Ph.  B.,  Editorial  Assistant,  Middletown,  Conn. 


LETTER  OF  TRANSMITTAL. 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

OFFICE  OF  EXPERIMENT  STATIONS, 

Washington,  D.  C.,  May  %5,  1904. 

SIR:  I  have  the  honor  to  transmit  herewith  and  recommend  for  pub- 
lication a  summary  showing  the  scope  of  the  cooperative  nutrition 
investigations  carried  on  under  the  auspices  of  this  Office.  This 
includes  an  account  of  the  origin  and  development  of  the  investiga- 
tions and  their  character,  data  regarding  the  collaborators  and  collab- 
orating institutions,  and  also  some  of  the  more  important  results 
obtained. 

Respectfully,  ,  A.  C.  TRUE, 

Director. 
Hon.  JAMES  WILSON, 

Secretary  of  Agriculture. 

3 


337240 


CONTENTS. 

Page, 

Introduction 5 

Organization  of  the  inquiry 7 

Scope  of  the  inquiry 8 

Distribution  of  the  work 10 

Some  results  of  nutrition  investigations 12 

Composition  of  food  materials «t 12 

Dietary  studies 13 

Digestion  experiments 16 

Metabolism  experiments  with  the  respiration  calorimeter 16 

Factors  for  digestibility  and  fuel  value  of  nutrients 17 

The  pecuniary  economy  of  food 18 

The  educational  influence  of  the  nutrition  investigations 19 

Conclusion 20 


ILLUSTRATIONS. 


Page. 

PLATE  I.  Fig.  1. — Bread  from  normal  flour  and  from  mixtures  of  normal  and 
extracted  flours.     Fig.  2. — Bread   from  normal   flour  and  from 

mixtures  of  normal  and  corn  flours 8 

II.  Composition  of  food  materials 12 

III.  Dinner  at  a  Chinese  truck  farm,  California 12 

IV.  General  view  of  the  respiration  calorimeter 16 

V.  Ground  plan  of  respiration  calorimeter  laboratory 16 

VI.  Pecuniarv  economv  of  food..  18 


INVESTIGATIONS  ON  THE  NUTRITION  OF  MAN  IN  THE 
UNITED  STATES. 


By  0.  F.  LANG  WORTHY,  Ph.  D.,  and  R.  D.  MILNER,  Ph.  B., 

Of  the  Office  of  Experiment  Stations. 


INTRODUCTION. 

During  the  past  few  years  the  experimental  study  of  the  food  and 
nutrition  of  both  domestic  animals  and  man  has  become  very  active  in 
the  United  States.  A  large  part  of  such  inquiry,  indeed  nearly  all  of 
that  which  has  to  do  with  domestic  animals,  is  carried  on  in  connec- 
tion with  the  agricultural  experiment  stations,  which  have  been  estab- 
lished within  the  past  twenty-eight  years  and  are  now  in  operation  in 
all  the  States  and  Territories  of  the  Union  except  the  Philippines. 

With  the  rise  of  the  experiment  stations  inquiries  into  the  composi- 
tion of  feeding  stuffs  and  their  appropriate  use  in  the  nutrition  of 
domestic  animals  were  undertaken,  and  have  ever  since  been  carried 
on  quite  actively.  Later  some  of  the  stations  undertook  similar  inves- 
tigations of  the  food  of  man,  and  in  recent  years  the  study  of  the  food 
and  nutrition  of  man  has  acquired  increased  importance  in  the  United 
States  from  the  extensive  investigations  that  have  been  made  and  are 
still  being  made  in  connection  with  and  as  a  part  of  the  work  of  the 
Department  of  Agriculture  in  cooperation  with  universities,  colleges, 
experiment  stations,  benevolent  institutions,  and  individual  investi- 
gators in  different  parts  of  the  country. 

There  had  been,  indeed,  a  considerable  amount  of  study  of  the  food 
of  man — and  of  domestic  animals  also — before  the  experiment  stations 
were  established.  An  interesting  investigation  on  the  subject  of 
human  nutrition  was  prosecuted  by  J.  R.  Young,  in  Philadelphia,  as 
early  as  1803,  and  perhaps  almost  continuously  since  that  time  valu- 
able information  on  food  and  nutrition  has  been  accumulated  by  phy- 
sicians, by  State  boards  of  health,  and  by  specialists  in  physiology, 
hygiene,  and  dietetics.  The  United  States  Government,  through  its 
various  branches,  has  contributed  much  of  value  to  the  science  of 
nutrition.  The  War  Department  and  the  Navy  Department,  in  their 
efforts  to  secure  the  most  satisfactory  diet  for  the  soldiers  and  sailors, 
have  collected  a  great  deal  of  information  and  conducted  many  inves- 
tigations which  have  to  do  with  the  subject  of  dietetics,  while  the 


6 

importance  of  their  investigations  dealing  with  the  hygiene  of  the 
subject  can  hardly  be,  overestimated.  In  connection  with  the  United 
States  Census  a  large  amount  of  data  regarding  foods  has  been 
secured,  the  major  portion  of  which  has  to  do  with  production  and 
distribution,  though  many  analyses  have  been  reported  in  census  pub- 
lications, as  well  as  special  studies  of  foods,  food  industries,  and 
related  topics.  Of  very  noteworthy  importance  are  the  studies  of 
anatytical  methods,  of  the  chemical  composition  of  foods,  and  of  food 
adulteration,  conducted  in  the  Bureau  of  Chemistry  of  the  Department 
of  Agriculture  by  its  chief,  Prof.  H.  W.  Wiley,  and  others. 

A  complete  historical  review  of  investigations  on  food  and  nutrition 
of  man  in  the  United  States  would  necessarily  include  an  account  of 
the  above  inquiries  and  others  not  referred  to  here.  The  purpose  of 
the  present  article,  however,  is  to  give  a  brief  resume  of  the  coopera- 
tive inquiry  into  the  food  and  nutrition  of  man  now  being  carried  on 
under  the  auspices  of  the  Office  of  Experiment  Stations  of  the  Depart- 
ment of  Agriculture,  and  to  indicate  the  progress  and  results  of  that 
enterprise.  This  inquiry  had  its  inception  in  a  study  of  the  chemical 
composition  of  food  fishes  and  invertebrates  undertaken  by  Prof. 
W.  O.  Atwater  in  1877  and  continued  until  1882,  in  the  chemical  labora- 
tory of  Wesleyan  University,  Middletown,  Conn.,  at  the  instance  of 
Prof.  S.  F.  Baird,  Secretary  of  the  Smithsonian  Institution  and  United 
States  Commissioner  of  Fish  and  Fisheries.  In  connection  with  this 
work  similar  investigations  of  other  animal  and  some  vegetable  prod- 
ucts were  undertaken  a  little  later  (1884)  on  behalf  of  the  United 
States  National  Museum.  About  the  same  time  (1886)  the  first 
extended  inquiry  into  the  statistics  of  food  consumption  in  the  United 
States  was  undertaken  by  Hon.  Carroll  D.  Wright,  as  chief  of  the 
Massachusetts  Bureau  of  Statistics  of  Labor,  and  the  chemical  results 
were  computed  and  reported  by  Professor  Atwater.  In  1890  the 
Connecticut  (Storrs)  Experiment  Station,  under  the  direction  of  Pro- 
fessor Atwater,  in  cooperation  with  Hon.  Carroll  D.  Wright  as  United 
States  Commissioner  of  Labor,  began  a  series  of  dietary  studies  which 
continued  for  several  years.  Except  for  the  inquiries  under  the  aus- 
pices of  the  Massachusetts  labor  bureau,  the  United  States  Department 
of  Labor,  and  the  Connecticut  (Storrs)  Experiment  Station,  the  larger 
share  of  the  expenses  of  this  work  was  borne  by  private  individuals. 
The  results  of  these  inquiries  gradually  attracted  attention.  The 
bearing  of  such  research  upon  household,  agricultural,  and  national 
economics  became  evident,  and  as  early  as  1890  steps  were  taken  to 
secure  an  appropriation  from  Congress  to  enlarge  its  scope  and  use- 
fulness, but  nothing  definite  was  accomplished  there  until  1894.  In 
that  year  the  experiment  stations  were  authorized  by  Congress  to 
cooperate  with  the  Secretary  of  Agriculture  in  studying  the  food  and 
nutrition  of  man,  and  were  called  upon  to  report  to  him  the  results  of 


such  investigations  as  they  might  carry  out.  At  the  same  time  Con- 
gress provided  an  especial  appropriation  to  enable  the  Secretary  of 
Agriculture  to  prosecute  inquiries  in  this  direction.  The  sums  pro- 
vided by  Congress  for  nutrition  investigations  for  the  Department  of 
Agriculture  have  been  since  the  beginning: 


Fiscal  year. 

Amount. 

Fiscal  year. 

Amount. 

1894  95 

$10,000 

1900-1901  

$17,  500 

1895_96 

15  000 

1901-2                                 

20,000 

1896  97                                              

15,000 

1902-3  

20;  000 

1897  98 

15,000 

1903-4  

20,000 

1898-99 

15  OCO 

1904-5             

20.000 

1899  1900                                              

15,OCO 

These  amounts  have  been  increased  by  contributions  from  other 
sources  which  are  not  easily  estimated  in  terms  of  money,  since  they 
consist  in  large  part  of  the  use  of  laboratories,  apparatus,  and  other 
facilities  for  research,  the  counsel  and  help  of  experts,  and  other  gra- 
tuitous service.  The  State  of  Connecticut  makes  an  annual  appropri- 
ation, which  is  used  under  Professor  Atwater's  direction,  for  nutrition 
investigations,  in  cooperation  with  the  United  States  Department  of 
Agriculture.  Part  of  the  appropriation  made  by  the  State  of  Illinois 
to  its  State  University  and  experiment  station  is  regularly  expended 
in  the  study  of  problems  related  to  the  food  and  nutrition  of  man.  A 
considerable  number  of  other  experiment  stations,  educational  institu- 
tions, philanthropic  organizations,  and  private  individuals  have  given 

sums  of  money  to  promote  the  cooperative  inquiry. 

• 

ORGANIZATION  OF  THE  INQUIRY. 

The  nutrition  investigations  of  the  Department  of  Agriculture  are 
conducted  through  the  Office  of  Experiment  Stations,  the  general 
supervision  of  these  investigations  having  been  assigned  by  the  Sec- 
retary of  Agriculture  to  that  Office.  The  immediate  supervision  of 
the  enterprise  has  been  entrusted  to  Prof.  W.  O.  Atwater,  chief  of 
nutrition  investigations. 

For  many  years  Professor  Atwater,  in  connection  with  his  duties  as 
professor  of  chemistry  at  Wesleyan  University,  has  devoted  much  of 
his  time  to  investigations  relating  to  the  nutrition  of  man,  introducing 
into  the  United  States  the  German  methods  of  studying  nutrition 
problems.  He  was  the  first  director  of  the  Office  of  Experiment  Sta- 
tions, and,  after  his  services  in  this  capacity  had  terminated,  the  Depart- 
ment was  very  fortunate  in  securing  his  cooperation  as  special  agent 
in  charge  of  its  nutrition  investigations.  The  very  great  development 
of  this  enterprise,  as  evidenced  by  the  number  and  extent  of  the  inves- 
tigations carried  on,  the  public  interest  which  has  been  aroused,  the 
demand  for  information  from  private  individuals,  physicians,  and 
teachers,  and  the  practical  application  of  the  results  already  obtained 


8 

in  numerous  instances  where  rational  and  economical  feeding  was 
a  necessit}^,  are  indications  that  the  investigations  have  been  well 
managed. 

The  administrative  and  editorial  work  connected  with  the  nutrition 
investigations  is  conducted  at  Washington,  D.  C.,  and  Middletown, 
Conn.  The  investigations  themselves  are  prosecuted  in  different 
places,  the  general  policy  being  to  make  particular  institutions  centers 
of  investigations  along  special  lines.  Part  of  the  fund  provided  by 
Congress  is  expended  under  the  sole  and  immediate  care  of  the  Depart- 
ment; part  is  distributed  among  scientific,  educational,  and  philan- 
thropic institutions  in  various  places  from  Maine  to  California,  and 
used  not  so  much  as  compensation  for  services  as  for  encouragement 
to  research.  The  cooperating  institutions  have  in  most  cases  contrib- 
uted material  assistance,  especially  as  regards  laboratory  rooms  and 
appliances  and  the  services  of  skilled  investigators. 

SCOPE  OF  THE  INQUIRY. 

Investigations  on  the  food  and  nutrition  of  man  include  the  study 
of  two  branches  of  the  subject,  which,  though  quite  intimately  related 
and  both  valuable,  are  nevertheless  of  importance  in  different  ways. 
One  branch  comprises  a  study  of  the  chemical  composition  of  dif- 
ferent food  materials,  an  investigation  that  is  purety  analytical,  but  a 
necessary  preliminary  to  studies  in  the  other  branch  of  the  subject, 
which  comprises  researches  into  the  laws  of  nutrition.  The  former  is 
concerned  simpjy  with  the  chemistry  of  food,  while  the  latter  has  to 
do  with  the  physiology,  the  physics  and  chemistry,  of  the  nutrition  of 
man,  together  with  the  economic  and  sociological  application  of  the 
fundamental  principles  of  nutrition  to  the  diet  of  persons  in  different 
localities  and  under  different  conditions  in  life. 

The  cooperative  nutrition  investigations  include  studies  of  several 
branches  of  the  subject,  especial  attention  having  been  paid  to  studies 
of  the  kinds  and  amounts  of  food  consumed  by  individuals,  families, 
institutions,  etc.;  experiments  on  the  digestibility  of  food  materials; 
and  researches  into  the  fundamental  laws  of  nutrition,  including  par- 
ticularly investigations  with  the  bomb  calorimeter  and  the  respiration 
calorimeter.  In  addition  to  these,  collateral  questions  of  a  wide 
variety  have  also  received  much  attention.  A  brief  statement  of  the 
general  lines  along  which  the  inquiries  have  been  conducted  is  as 
follows: 

Studies  of  actual  dietaries  in  order  to  learn  the  kinds,  amounts,  and  costs  of  food 
materials  consumed  by  persons  in  different  localities,  of  different  occupations,  ages, 
and  sex,  and  under  varying  conditions. 

Special  studies  of  cereal  products,  including  nutritive  value  of  different  milling 
products  of  wheat;  nutritive  value,  quality,  and  digestibility  of  bread  from  hard  and 
soft  wheat  flours  of  different  grades,  as  "graham,"  "entire  wheat,"  and  ''standard 
patent"  grades;  bakery  experiments  to  determine  the  cost  of  making  bread,  and  the 


U.  S.  Dept.  of  Agr.,  Office  of  Expt.  Stations,  713. 


PLATE  I. 


FIG.  1  .—BREAD  FROM  NORMAL  FLOUR  AND  FROM  MIXTURES  OF  NORMAL  AND 
EXTRACTED  FLOURS. 

A,  Normal  flour;  B,  flour  with  about  one-half  of  the  gliadin  extracted;  C,  one-half  normal  and 
one-half  gliadin-extracted  flour. 


FIQ.  2.— BREAD  FROM  NORMAL  FLOUR  AND  FROM  MIXTURES  OF  NORMAL  AND  CORN 

FLOURS. 

A,  Normal  flour;  B,  normal  flour  and  20  per  cent  corn  flour;  C,  normal  flour  and  10  per  cent 

corn  flour. 


losses  in  nutritive  value  during  the  process  of  bread  making.  Plate  I  illustrates 
the  results  obtained  in  some  of  these  studies  of  the  effect  and  the  importance  of  the 
various  constituents  of  flour  upon  the  character  of  the  bread.  In  fig.  1,  bread  A 
was  made  from  normal  flour  and  breads  B  and  C  from  flour  which  contained  abnor- 
mal amounts  of  gliadin,  one  of  the  important  nitrogenous  constituents  of  flour.  In 
fig.  2,  A  represents  normal  bread  and  B  and  C  bread  made  from  flour  in  which  the 
starch  content  was  rendered  abnormal  by  adding  corn  flour. 

Special  studies  of  meats,  including  the  nutritive  value  of  raw  and  cooked  meats; 
the  relative  digestibility  of  meats  cooked  in  different  ways;  the  nature  and  amount 
of  losses  occurring  during  the  cooking  of  meats  in  different  ways. 

Experiments  on  the  digestibility  of  vegetables  and  the  losses  in  different  vegetables 
during  cooking. 

Experiments  on  the  digestibility  and  nutritive  value  of  legumes,  including  beans 
and  cowpeas. 

Studies  of  the  comparative  economy,  digestibility,  and  nutritive  value  of  fruits  and 
nuts. 

A  convenient  and  comparatively  inexpensive  form  of  bomb  calorimeter  has  been 
developed  and  is  used  in  determining  the  amounts  of  potential  energy  in  food  mate- 
rials, excretory  products,  and  other  substances. 

Metabolism  experiments  have  been  carried  on  with  men  in  the  respiration  calo- 
rimeter. The  objects  of  these  investigations  have  been:  To  develop  an  apparatus 
and  method  for  the  accurate  measurement  of  the  income  and  outgo  of  the  animal 
organism  as  expressed  in  terms  of  matter  and  energy;  to  confirm  the  belief  that  the 
law  of  the  conservation  of  energy  obtains  in  the  living  body;  and,  after  such  demon- 
stration of  the  accuracy  of  the  apparatus  and  methods  and  of  the  action  of  the  law  of 
the  conservation  of  energy,  to  study  some  of  the  more  important  fundamental  laws 
of  nutrition. 

The  fact  was  early  recognized  that  compilations  and  summaries  of  the  investiga- 
tions which  have  been  carried  on  in  Europe  and  this  country  were  necessary.  In 
order  to  conduct  any  kind  of  research  most  efficiently  it  is  necessary  to  know  what 
has  been  accomplished  by  others  in  order  that  the  investigator  may  profit  by  their 
results  and  that  an  unnecessary  duplication  of  effort  may  be  avoided.  Furthermore, 
summaries  of  previous  investigations  are  of  great  value  in  suggesting  lines  of  research 
and  in  awakening  the  interest  of  investigators  by  showing  past  achievements.  To 
this  end  the  current  literature  of  the  nutrition  of  man,  which  is  now  quite  volumi- 
nous, is  being  regularly  followed  up,  and  such  abstracts  and  compilations  are  being 
made  as  will  promote  the  interest  of  the  investigations. 

The  rapid  accumulation  of  material  which  must  be  made  ready  for  publication 
necessitates  a  large  amount  of  editorial  work.  The  results  of  the  investigations  are 
given  in  bulletins,  some  of  popular  nature  and  others  technical  in  character.  The 
results  of  analyses  of  food  materials  in  the  United  States  have  been  compiled  and 
printed  in  a  bulletin  for  popular  use,  which  is  revised  from  time  to  time  as  data 
accumulate.  The  results  of  dietary  studies  also  appear  in  bulletins  prepared  for 
popular  use.  The  data  of  the  digestion  experiments  and  those  obtained  in  investi- 
gations with  the  respiration  calorimeter  are  given  in  bulletins  more  or  less  technical 
in  character,  and  intended  rather  for  the  scientific  student  of  the  subject.  Abstracts 
of  the  current  literature  of  the  subject  of  food  and  nutrition  appear  regularly  in  the 
Experiment  Station  Record.  More  popular  abstracts  of  some  of  this  work,  particu- 
larly that  of  American  investigators,  appear  in  the  series  of  Farmers'  Bulletins, 
entitled  "Experiment  Station  Work." 

The  correspondence  connected  with  the  nutrition  investigations  has  grown  to  very 
considerable  dimensions. 


10 
DISTRIBUTION  OF  THE  WORK. 

The  following  is  a  brief  summaiy,  alphabetical^  b}r  States,  of  the 
localities  in  which  the  inquiries  have  been  prosecuted,  the  cooperating 
institutions  and  investigators,  and  the  nature  of  the  .investigations 
conducted : 

Alabama. — Tuskegee  Normal  and  Agricultural  Institute;  Prof.  Booker  T.  Wash- 
ington. Alabama  Polytechnic  Institute  and  the  Alabama  Experiment  Station, 
Auburn;  Prof.  B.  B.  Ross.  Study  of  the  food  consumption  of  the  negroes  in  the 
"black  belt"  of  Alabama,  and  of  the  character  and  nutritive  value  of  the  food 
materials  used  by  negroes. 

California. — University  of  California;  Prof.  M.  E.  Jaffa.  Cost  and  nutritive  value  of 
California  food  materials,  especially  fruits  and  nuts;  dietary  studies  of  infants, 
athletes,  professional  men,  fruitarians,  and  Chinese;  digestion  and  nitrogen  meta- 
bolism experiments  with  an  infant  and  with  fruitarians. 

In  addition,  Mr.  W.  C.  Blasdale,  instructor  in  chemistry  at  the  university,  made  a 
detailed  study  of  the  nutritive  and  economic  value  of  Chinese  vegetable  food  materials 
found  in  the  markets  of  San  Francisco. 

Connecticut. — Wesleyan  University  and  Storrs  Experiment  Station;  Prof.  W.  O. 
Atwater,  Prof.  F.  G.  Benedict,  and  associates.  Cost  and  nutritive  value  of  various 
food  materials;  dietary  studies;  digestion  and  nitrogen  metabolism  experiments; 
development  of  bomb  calorimeter  and  respiration  calorimeter,  and  of  methods  of 
using  these  in  investigations  of  the  metabolism  of  matter  and  energy  in  the  human 
body. 

The  work  of  the  office  of  Professor  Atwater,  who  is  chief  of  the  nutrition  investi- 
gations, has  also  included  the  planning  and  direct  supervision  of  the  cooperative  inves- 
tigations in  different  parts  of  the  country,  the  compilation  of  the  results  of  nutrition 
investigations  in  the  United  States  and  foreign  countries,  editorial  work  in  the  prepa- 
ration of  the  reports  of  the  cooperators  for  publication,  and  a  large  correspondence 
relating  to  the  investigations. 

Georgia. — University  of  Georgia;  Dr.  H.  C.  White.  Dietary  studies  of  college 
boarding,  clubs,  and  of  families  in  the  mountain  regions  of  Georgia. 

Illinois. — Hull  House,  Chicago;  Miss  Jane  Addams  and  Miss  Caroline  Hunt;  and 
Lewis  Institute,  Chicago;  Prof.  G.  N.  Carman.  Dietary  studies. 

Mrs.  Ellen  H.  Richards  and  Miss  Amelia  Shapleigh  also  carried  on  dietary  studies 
with  the  cooperation  of  Hull  House.  The  data  obtained  were  eventually  submitted 
to  the  Department  of  Agriculture  for  calculation  and  publication. 

University  of  Illinois;  Prof.  H.  S.  Grindley.  Cost  and  nutritive  value  of  food 
materials;  dietary  studies:  special  investigations  on  meat,  including  losses  in  different 
modes  of  cooking,  and  digestibility  of  meats  cooked  in  different  ways.  Prof.  Isabel 
Bevier  and  Miss  Elizabeth  Sprague.  Studies  in  cooking  meat. 

Indiana.— Purdue  University;  Prof.  W.  E.  Stone.     Dietary  studies. 

Maine. — University  of  Maine  and  Maine  Experiment  Station;  Prof.  W.  H.  Jordan, 
Prof.  C.  D.  Woods,  and  L.  H.  Merrill.  Studies  of  the  nutritive  value  of  a  number 
of  food  materials;  feeding  experiments  to  determine  the  value  of  milk  in  the  diet; 
and  dietary  studies  and  digestion  experiments,  especially  with  lumbermen  in  the 
Maine  woods.  Experiments  on  the  digestibility  and  nutritive  value  of  bread  made 
from  different  grades  of  flour;  study  of  experimental  methods,  particularly  means  of 
separation  of  feces  in  digestion  experiments  and  determination  of  metabolic  nitrogen 
in  feces. 

Maryland.— Mrs.  Mary  Hinman  Abel  cooperated  with  the  Department  in  the 
preparation  of  summaries  of  data  regarding  the  nutritive  value  and  place  in  the  diet 
of  sugar  and  of  leguminous  vegetables,  and  in  connection  with  this  work  made  a 
number  of  cooking  experiments. 


11 

Massachusetts. — School  of  Housekeeping,  Boston;  Miss  Lydia  Southard,  Miss 
Susannah  Usher,  and  Miss  Bertha  M.  Terrill  carried  on  dietary  studies,  in  a  number 
of  which  the  attempt  was  made  to  regulate  the  cost  of  the  food  and  at  the  same  time 
make  it  compare  with  commonly  accepted  dietary  standards.  The  results  of  these 
investigations  were  submitted  to  the  Department  for  calculation  and  publication. 

Harvard  University,  Cambridge;  Dr.  E.  A.  Darling.  Dietary  studies  of  athletes. 
Prof.  C.  R.  Sanger  and  Mr.  Edward  Mallinckrodt,  jr.  Dietary  studies  of  students. 

Springfield  Bible  Normal  College;  Miss  Bertha  M.  Terrill.  Dietary  study.  In 
this  investigation  the  attempt  was  made  to  regulate  the  cost  of  the  daily  food  and  at 
the  same  time  make  it  correspond  with  the  commonly  accepted  dietary  standards. 
The  results  were  submitted  to  the  Department  for  calculation  and  publication. 

Minnesota. — University  of  Minnesota  and  Minnesota  Experiment  Station;  Prof. 
Harry  Snyder.  Study  of  losses  in  cooking  vegetables  and  in  making  bread;  special 
studies  of  cereal  products,  including  relative  nutritive  value  of  milling  products  of 
wheat,  and  digestibility  and  nutritive  value  of  bread  made  from  different  grades  of 
hard  and  soft  wheat  flours.  A  considerable  part  of  the  latter  investigation  is  carried 
on  coordinately  with  similar  work  by  Prof.  C.  D.  Woods  at  the  Maine  Experiment 
Station. 

Missouri. — University  of  Missouri;  Prof.  H.  B.  Gibson.  Dietary  studies;  investi- 
gation of  the  relative  consumption  of  different  kinds  of  meat  and  bread. 

New  Jersey. — New  Jersey  Experiment  Station;  Prof.  E.  B.  Voorhees  and  Mr.  L.  A. 
Voorhees.  Dietary  study;  studies  of  the  cost  and  composition  of  milk  and  of  bread, 
of  the  relative  cost  of  bread  and  the  raw  ingredients  from  which  it  was  made,  and  of 
the  losses  in  baking  bread. 

New  Mexico. — New  Mexico  College  of  Agriculture  and  Mechanic  Arts  and  New 
Mexico  Experiment  Station;  Prof.  Arthur  Goss.  Study  of  the  relative  nutritive 
value  of  native  food  materials,  especially  native  beef,  and  of  the  food  consumption  of 
native  Mexican  families. 

New  York. — Mrs.  Louise  E.  Hogan  studied  the  history  and  methods  of  teaching 
cookery  in  the  public  schools  of  New  York  City. 

-  Cornell  University,  Ithaca;  Prof.  R.  C.  Carpenter.     Measurements  of  mechanical 
work,  and  studies  of  the  efficiency  of  man  as  a  machine. 

New  York  Association  for  the  Improvement  of  the  Condition  of  the  Poor  and  New 
York  Christian  Alliance,  New  York;  Dr.  Isabelle  Delaney.  Dietary  studies  of  poor 
families  in  congested  districts  in  New  York  City. 

Columbia  University,  New  York;  Dr.  H.  C.  Sherman.  Digestion  experiments  and 
investigations  on  the  metabolism  of  nitrogen,  sulphur,  and  phosphorus  in  the  human 
body. 

North  Dakota.—  North  Dakota  Agricultural  College;  Prof.  E.  F.  Ladd.  Dietary 
study. 

Ohio. — Lake  Erie  College;  Prof.  Isabel  Bevier  and  Miss  Elizabeth  Sprague.  Dietary 
study. 

Pennsylvania. — College  Settlement,  Philadelphia;  Mrs.  Ellen  H.  Richards  and  Miss 
Amelia  Shapleigh.  Dietary  studies  of  families  of  limited  income  were  undertaken, 
the  data  obtained  being  submitted  to  the  Department  for  calculation  and  publication. 

Pennsylvania  College  for  Women,  Pittsburg;  Prof.  Isabel  Bevier.  Dietary  studies; 
study  of  the  composition  and  cost  of  bakers'  bread  in  Pittsburg  and  of  the  changes 
in  the  materials  of  bread  during  baking. 

Tennessee. — University  of  Tennessee;  Prof.  C.  E.  Wait.  Analyses  of  Tennessee 
food  materials;  dietary  studies;  experiments  on  the  effect  of  muscular  work  upon 
the  digestibility  of  food  and  the  metabolism  of  nitrogen;  studies  of  the  digestibility 
and  nutritive  value  of  legumes. 

Vermont.— Vermont  Experiment  Station;  Prof.  J.  L.  Hills.  Dietary  studies  of 
farmers'  families. 


12 

I 'iryinia.— Hampton  Normal  and  Agricultural  Institute;  Dr.  H.  B.  Frissell.  Dietary 
studies  of  negroes. 

Under  special  authorization  Miss  Isabel  Bevier  also  made  similar  studies  in  another 
part  of  the  State. 

State  University;  Prof.  J.  W.  Mallett.  Studies  of  the  physiological  effects  of  meat 
bases,  i.  e.,  creatin  and  creatinin. 

Washington,  D.  C. — Besides  the  general  supervision  of  the  plans  and  expenditures, 
the  work  of  the  Washington  office  in  relation  to  the  nutrition  investigations  has 
included  the  preparation  of  popular  bulletins;  the  compilation  of  technical  summa- 
ries of  investigations;  editorial  work  in  perfecting  the  details  of  reports  of  investiga- 
tions; collection  of  bibliographical  data;  the  abstracting  of  the  literature  of  nutrition, 
partly  for  publication  in  the  Experiment  Station  Record;  the  conducting  of  a  large 
correspondence  growing  out  of  nutrition  investigations,  and  the  distribution  of  pub- 
lications on  this  subject,  This  work  is  in  charge  of  Dr.  C.  F.  Langworthy. 

Cooperating  with  the  U.  S.  Department  of  the  Interior  a  series  of  studies  of  food 
consumption  has  been  conducted  in  the  Government  Hospital  for  the  Insane  at 
Washington,  D.  C.  The  results  obtained  were  interesting  and  valuable,  and  are 
being  utilized  to  make  the  diet,  which  was  found  to  be  ample  and  of  good  quality, 
conform  to  theoretical  requirements.  This  cooperative  investigation  was  begun  by 
Dr.  A.  B.  Richardson  and  was  continued  by  his  successor,  Dr.  W.  A.  White,  the 
experimental  work  having  been  carried  on  by  Mr.  H.  A.  Pratt. 

Mention  should  also  be  made  here  of  other  investigations  which, 
while  not  strictly  a  part  of  the  cooperative  inquiry,  are  yet  so  closely 
related  to  it  that  they  may  be  included  in  this  summary: 

On  behalf  of  the  New  York  State  Commission  in  Lunacy  an  extended  series  of 
studies  of  the  food  consumption  of  the  New  York  hospitals  for  the  insane  was  car- 
ried on  under  the  supervision  of  Professor  Atwater. 

A  study  of  the  food  consumption  at  the  Elmira  Reformatory,  in  New  York  State, 
was  also  made  under  the  supervision  of  Professor  Atwater. 

A  sum  of  money  has  been  granted  by  the  Carnegie  Institute  to  Professor  Atwater 
for  the  development  of  accessory  apparatus  and  methods  for  determination  of  oxygen 
in  connection  with  the  experiments  in  the  respiration  calorimeter,  and  for  investiga- 
tions of  the  income  and  outgo  of  oxygen  in  the  animal  organism.  The  apparatus  has 
been  completed  and  found  to  be  very  accurate  (see  p.  16). 

SOME  RESULTS  OF  NUTRITION  INVESTIGATIONS. 

Among  the  more  important  results  obtained  in  these  investigations 
are  those  from  studies  of  the  composition  of  food  material,  from 
dietary  studies,  digestion  experiments,  and  investigations  with  the 
respiration  calorimeter. 

COMPOSITION   OF   FOOD   MATERIALS. 

One  result  of  the  investigations  of  food  and  nutrition  in  the  United 
States,  including  both  the  work  done  as  a  part  of  the  cooperative 
inquuy  and  that  cairied  on  in  other  connections,  is  that  we  have  now 
a  tolerably  clear  idea  of  the  composition  and  nutritive  values  of  our 
ordinal y  American  food  materials.  In  the  latent  revised  edition  of  a 


U.  S.  Dept.  of  Agr.,  Office  of  Expt.  Stations,  713. 


PLATE  II. 


Wafer        Refuse. 


COMPOSITION  OF  FOOD  MATERIALS.    NUTRITIVE  INGREDIENTS,  REFUSE,  AND  FUEL 

VALUE. 


U.  S.  Dept.  of  Agr.,  Office  of  Expt  Stations,  713. 


PLATE  III. 


13 

bulletin «  published  in  1903,  in  which  these  results  are  compiled,  the 
total  number  of  analyses  included  was  4,063.  Of  these,  1,618  were  of 
animal  foods,  2,375  of  vegetable  foods,  and  70  of  unclassified  foods. 

At  the  present  time  the  number  of  analyses  thus  compiled  is  more 
than  4,500  and  is  still  rapidly  increasing.  They  are  now  derived 
more  largely  from  other  sources  than  the  cooperative  nutrition  investi- 
gations, because  in  connection  with  the  latter  they  are  made  only  when 
necessary,  as  in  digestion  and  metabolism  experiments.  They  are  no 
longer  made  simply  to  increase  the  amount  of  such  data  available. 
Plate  11  shows  in  graphic  form  the  composition  and  fuel  value  of  some 
of  the  more  common  food  materials. 

DIETARY  STUDIES. 

The  number  of  studies  of  the  actual  food  consumption  of  people  of 
different  classes  that  have  formed  part  of  the  cooperative  inquiry  in 
different  parts  of  the  United  States  is  now  over  500.  These  include 
studies  of  families  of  day  laborers,  farmers,  mechanics,  and  men  in 
professional  life;  of  people  in  congested  districts  of  the  slums  of  New 
York  and  Chicago,  and  poor  families  in  other  cities;  of  negroes  in  the 
South;  of  Spaniards  in  the  extreme  Southwest;  and  of  Chinese  and 
fruitarians  on  the  Pacific  coast.  In  a  large  number  of  these  studies 
actual  analyses  were  made  of  food  materials  and  of  waste.  In  addition 
to  the  above,  which  were  made  entirely  as  a  part  of  the  cooperative 
nutrition  investigations,  nearly  half  as  many  studies  of  a  similar 
nature  not  directly  related  to  the  cooperative  inquiry  have  also  been 
completed.  The  latter  include  studies  in  private  families,  in  boarding- 
houses  and  clubs  of  men  and  women  in  colleges,  in  hospitals  for  the 
insane,  and  in  other  institutions.  The  total  number  of  persons — men, 
women,  and  children — included  in  all  these  studies  is  not  far  from 
15,000. 

Results  of  some  of  the  more  important  dietary  studies  thus  far  made 
are  summarized  in  the  following  table.  These  are  typical  of  the 
studies  already  published.  The  data  of  a  considerable  number  of 
other  studies  are  now  being  prepared  for  publication. 

«U.  S.  Dept.  Agr.,  Office  of  Experiment  Stations  Bui.  28:  The  Chemical  Composi- 
tion of  American  Food  Materials.  Revised  edition,  1903. 


14 

Summarized  results  of  dietary  studies  in  the  United  States. 
[Quantities  per  man  per  day.] 


..  •    ', 

Number  of  studies  in- 
cluded in  averages. 

Actually  eaten.              Digestible. 

| 

1 

| 

£ 

Nutritive  ratio. 

Protein. 

1' 

Carboh  ydrates. 

Protein. 

I 

Carbohydrates. 

PERCOXS  WITH   ACTIVE  WORK. 

Rowing  clubs  in  New  England 

7 
3 

2 

10 
14 
12 

2 

14 
15 

11 

11 

2 

20 
19 
4 
5 

8 

1 
10 
4 
1 
1 
1 
6 

Gms. 
155 
186 

226 

97 
103 
101 

120 

104 
107 

112 

93 

80 

62 
109 
103 
118 
115 

66 
137 
94 
115 
135 
144 
50 

175 
150 

125 
112 
100 
90 

Gms. 
177 
186 

354 

130 
150 
116 

147 

125 

148 

'  80 

95 
95 

132 
159 
111 
158 
101 

19 
103 
71 
113 
76 
95 
102 

(«) 
(«) 

(a) 

(»3 

(a) 
(«) 

Gms. 
440 
651 

634 

467 
402 
344 

534 

423 
459 

305 

407 
308 

436 
444 
391 
345 
360 

254 
418 
613 
289 
566 
640 
237 

(a) 
(a) 

(0) 

(a) 
(«) 
(a) 

Gms. 
143 
171 

208 

89 
95 
93 

110 

96 

98 

103 

86 
74 

57 
100 
95 
109 
106 

61 
126 
86 
106 
124 
132 
43 

161 
138 

115 
103 
92 
83 

Gms. 
168 
177 

336 

124 
143 
110 

140 

119 
141 

76 

90 
90 

125 
151 
105 
150 

96 

18 
98 
67 
107 
72 
90 
92 

(«) 

(a) 

(a) 

(") 
(a) 

(«) 

Gms. 
427 
631 

615 

453 
390 
334 

518 

410 
445 

296 

395 

299 

423 
342 
379 
335 
349 

246 
405 
595 
281 
549 
621 
225 

W 
(a) 

(*) 

(a) 

(«) 
(") 

Cols. 
3,955 
5,005 

6,590 

3,415 
3,355 
2,810 

3,925 

3,220 
3,580 

2,380 

2,845 
2,400 

3,165 
3,  625 
2,965 
3,260 
2,800 

1,450 
3,135 
3,460 
2,  620 
3,480 
3,980 
2,055 

5,500 
4,150 

3,400 
3,050 

•2,  700 

2.  !.">(> 

1: 
5.6 
6 

6.6 

8.2 
7.5 
6.3 

7.6 

7.1 

7.8 

4.5 

6.9 
6.8 

12.4 
6.8 
6.5 
6.2 
5.3 

4.7 
5 
8.7 
4.9 
6.7 
6.2 
10 

7.2 
6.2 

6.2 
6.1 
6.1 
6.1 

Bicyclists  in  New  York  

Football  teams  in  Connecticut  and  Cali- 
fornia     

PERSONS  WITH  ORDINARY  WORK. 

Farmers'  families                          

Mechanics'  families  

Laborers'  families  in  large  cities 

Laborers'  families  in  more  comfortable 
circumstances 

PROFESSIONAL  MEN. 

Lawvers  teachers  etc 

College  clubs  

MEN  WITH  LITTLE  OR  NO  EXERCISE. 

Men  in  respiration  calorimeter 

PERSONS  IN   DESTITUTE  CIRCUMSTANCES. 

Poor  families  in  New  York  City 

Laborers'  families  in  Pittsburg,  Pa  

MISCELLANEOUS. 

Negro  families  in  Alabama  

Negro  families  in  \  irginia                    .   . 

Italian  families  in  Chicago  

French  Canadians  in  Chicago    

Bohemian  families  in  Chicago 

Inhabitants  of  Java  Village,  Columbian 
Exposition  1893 

Russian  Jews  in  Chicago 

Mexican  families  in  New  Mexico  

Chinese  dentist  in  California 

Chinese  laundrvmen  in  California 

Chinese  farm  laborers  in  California  
Fruitarians 

DIETAF.Y  STANDARDS. 

Man  with  very  hard  muscular  work 

Man  with  hard  muscular  work  (Atwater) 
Man  with  moderately  active  muscular 
work  (Atwater)         



Man  with  light  to  moderate  muscular 
work  (Atwater) 

Man  at  "sedentary"  or  woman  with 
moderatelv  active  work  (Atwater) 

Woman  at  1'ight  to  moderate  muscular 
work  (Atwater)    

i  Fats  and  carbohydrates  in  sufficient  amounts  to  furnish,  together  with  the  protein,  the  indicated 
amount  of  energy. 

The  figures  in  the  above  table  show  both  the  total  nutrients  in  the 
food  consumed,  as  calculated  from  the  weights  and  chemical  composi- 
tion, and  the  digestible  nutrients  as  estimated  by  use  of  coefficients  of 
digestibility  based  upon  the  results  of  digestion  experiments.  The 


15 

fuel  value  of  the  diet — i.  e.,  the  amount  of  energy  actually  available  to 
the  body — has  been  calculated  by  the  use  of  the  most  recent  factors 
for  fuel  value  of  nutrients.  The  table  also  shows  dietary  standards 
that  have  been  proposed  on  the  basis  of  the  data  obtained  in  dietary 
studies,  digestion  experiments,  and  investigations  with  the  respiration 
calorimeter. 

From  the  results  of  these  investigations  it  is  apparent  that  varia- 
tions in  diet  are  in  part  such  as  naturally  follow  differences  in  the  actual 
food  supply;  but  they  are  also  influenced  to  some  extent  by  race  habits, 
and  to  a  still  larger  extent  by  the  amount  of  muscular  work  performed 
and  by  the  material  circumstances  of  the  consumer,  including  espe- 
cially his  income. 

One  of  the  most  important  ways  in  which  practical  application  may 
be  made  of  the  results  of  these  studies  to  the  benefit  of  large  numbers 
of  people  is  in  teaching  the  relative  nutritive  value  of  different  food 
materials  and  their  pecuniary  economy.  Much  is  already  being  done 
in  this  direction  in  different  parts  of  the  United  States. 

The  proper  nourishment  of  the  inmates  of  institutions  where  large 
numbers  must  be  fed,  such  as  schools,  reformatories,  prisons,  and  hos- 
pitals, is  a  subject  that  is  attracting  no  little  attention  at  the  present 
time.  In  many  instances  dietary  studies  have  been  made  in  schools, 
college  clubs,  etc.,  and  the  information  obtained  has  been  of  much  use. 
That  such  studies  have  been  found  to  have  a  practical  value,  and  that 
the  interest  in  them  is  widespread,  is  shown  by  the  fact  that  a  consid- 
erable number  have  been  undertaken  by  instructors  and  others  inter- 
ested, aside  from  those  carried  on  by  the  Department  of  Agriculture. 
The  dietary  studies  were  made  under  widely  varying  conditions.  Plate 
III,  showing  Chinese  farm  laborers  at  dinner,  is  an  illustration  of  this. 
These  laborers  were  one  of  the  groups  studied  in  an  investigation  of 
the  dietary  of  Chinese  on  the  Pacific  coast. 

As  a  result  of  such  studies  as  those  described  above,  the  dietary 
standards  included  in  the  table  have  been  suggested.  These  are 
intended  to  show  the  actual  food  requirements  of  persons  under  dif- 
ferent conditions  of  life  and  work,  and  how  these  requirements  may 
be  most  economically  and  efficiently  supplied  by  the  available  food 
materials.  It  is  not  claimed,  however,  that  the  food  each  day  should 
contain  exactly  the  kind  and  amounts  of  the  different  nutrients 
required  by  the  standards.  A  slight  deficiency  one  d&y  will  be  made 
good  by  an  excess  the  next,  the  body  serving  as  a  storehouse  for 
reserve  material.  Experience  has,  however,  shown  that  the  body  is 
best  nourished  when  through  long  periods  the  food  approximates  the 
requirements  of  the  so-called  standards.  Individual  requirements  and 
individual  peculiarities  will  always  affect  the  choice  of  foods. 

The  exact  knowledge  which  comes  with  such  researches  is  showing 
hosv  the  diet  of  large  classes  of  our  population  may  be  materially 
improved  while  often  its  cost  may  be  considerably  reduced. 


16 

DIGESTION    EXPERIMENTS. 

Nearly  600  digestion  experiments,  mostly  with  men  but  a  few  with 
women  and  children,  have  been  made  in  connection  with  the  nutrition 
investigations  of  the  Department.  In  connection  with  nearly  half  of 
these  the  income  and  outgo  of  nitrogen  has  been  determined,  thus 
making  them  nitrogen  metabolism  experiments  also. 

The  results  of  these  digestion  experiments  show  the  digestibility  of 
various  sorts  of  mixed  diet  and  of  individual  food  materials.  Taking 
these  results  into  account,  together  with  the  results  of  analyses,  we 
are  able  to  prepare  tables  showing  the  average  quantities  of  digestible 
nutrients  in  a  large  number  of  the  food  materials  in  most  common  use. 

METABOLISM     EXPERIMENTS    WITH    THE    RESPIRATION    CALO- 
RIMETER. 

From  the  more  purely  scientific  standpoint,  the  interest  of  this 
cooperative  nutrition  inquiry  culminates  in  the  experiments  with  the 
respiration  calorimeter.  These  have  for  their  object  the  study  of  the 
transformation  of  matter  and  energy  in  the  living  organism.  In  other 
words,  they  represent  an  inquiry  into  the  most  fundamental  and  most 
important  laws  of  nutrition.  The  apparatus  used  for  the  purpose, 
known  as  the  Atwater-Rosa  respiration  calorimeter,  which  has  been 
developed  in  connection  with  these  investigations,  suffices  for  the 
accurate  measurement  of  the  income  and  outgo  of  all  chemical  elements 
except  oxygen,  of  the  potential  energy  of  food,  of  unoxidized  excre- 
tory products,  of  body  material  gained  or  lost,  and  of  the  kinetic 
energy  given  off  from  the  body  in  the  forms  of  heat  and  external 
muscular  work'.  Accessory  apparatus  and  a  method  for  the  direct 
determination  of  income  and  outgo  of  oxygen  have  very  recently  been 
completed  by  Professors  Atwater  and  Benedict,  and  it  is  possible  with 
the  calorimeter  as  thus  modified  to  determine  directly  all  the  elements 
of  income  and  outgo  and  in  addition  to  study  the  respiratory  quotient 
which  is  known  to  be  a  very  delicate  index  of  the  processes  going  on 
in  the  body.  Plate  IV  gives  a  general  view  of  the  respiration  calorim- 
eter, and  Plate  V  a  ground  plan  of  the  calorimeter  laboratory. 

One  very  important  result  thus  far  obtained  by  the  use  of  this 
apparatus  is  what  amounts  practically  to  a  demonstration  that  the 
law  of  the  conservation  of  energy  applies  to  the  living  organism. 
The  proof  that  this  law  obtains  in  the  inorganic  world  was  one 
of  the  great  scientific  achievements  of  the  last  century.  It  has,  of 
course,  been  assumed  and  very  generally  believed  that  it  must  also 
apply  in  the  organic  world — in  the  living  being;  but  a  complete 
and  satisfactory  demonstration  has  not  hitherto  been  made,  although 
an  approximate  proof  was  found  in  a  number  of  European  experi- 
ments with  dogs.  As  the  outcome  of  6-i  experiments  by  Professors 


U.  S.  Dept.  of  Agr.,  Office  of  Expt.  Stations,  713. 


PLATE  IV. 


U.  S.  Dept.  of  Agr.,  Office  of  Expt.  Stations,  71  3. 


PLATE  V. 


•ffi 


r-F*         -T- 

i'fiii|Tiiiiii: 


17 

Atwater  and  Benedict,  and  their  associates,  at  Wesleyan  University, 
made  with  6  different  men,  covering  an  aggregate  of  one  hundred  and 
eighty-four  days,  the  ratio  of  the  potential  energy  of  the  material 
oxidized  in  the  body  to  the  energy  given  off  from  the  body  in  the 
forms  of  heat  and  muscular  work,  as  measured  by  the  respiration 
calorimeter,  is  as  1,000  to  999.  The  same  ratio  of  1,000  to  999  was 
found  in  the  average  of  a  large  number  of  experiments  made  to  test 
the  accuracy  of  the  apparatus.  Closer  agreement  than  this  could  not 
be  looked  for. 

The  practical  usefulness  of  this  apparatus  and  method  of  inquiry 
will  be  realized  more  clearly  when  we  consider  that  it  gives  us  a  means 
for  measuring  more  exactly  than  has  hitherto  been  possible,  the  trans- 
formations of  matter  and  energy  which  take  place  in  the  bodies  of 
different  persons  with  different  kinds  and  amounts  of  food  or  in  fast- 
ing, and  under  widely  varying  conditions  of  muscular  and  mental 
activity.  The  experiments  furnish  a  mass  of  data  needed  for  various 
sciences  of  physiology  and  hygiene.  These  data  have  to  do  with 
food,  drink,  and  excretory  products  and  with  the  metabolic  processes 
and  changes  of  body  tissue  as  they  are  influenced  by  work,  sleep, 
diet,  temperature,  and  other  circumstances.  They  show  the  nutritive 
values  of  food  and  the  demands  of  the  body  in  health  and  disease. 
Incidentally  they  throw  valuable  light  on  problems  of  ventilation  and 
numerous  other  questions  of  hygiene.  They  supply  the  foundations 
of  the  doctrine  of  nutrition  and  belong  to  the  highest  order  of  scien- 
tific research. 

FACTORS  FOB  DIGESTIBILITY  AND  FUEL  VALUE  OF  NUTRIENTS. 

The  data  obtained  in  the  nutrition  investigations  may  be  used  in 
deducing  certain  factors  which  are  useful  in  various  ways  to  students 
and  investigators  of  similar  problems,  and  to  some  extent  also  to  those 
who  wish  to  make  practical  application  of  the  results.  Such  factors 
for  the  digestibility  and  fuel  value  of  -the  nutrients  of  ordinary  mixed 
diet  have  been  epitomized  by  Professor  Atwater  in  the  following 
table: 

32823—04 2 


18 


Factors  for  digestibility  and  fuel  value  of  nutrients  in  mixed  diet. 


Classes  of  food 
materials. 

Protein. 

Fat. 

Carbohydrates.         bjj* 

pi 

i 

5 

Fuel  value 
per  grain. 

P 

t;£j 

"Digestibility. 

Fuel  value 
per  gram. 

|| 

la 

If, 

8*3 

Digestibility. 

Fuel  value  1 
per  gram.  :<c  — 

•       «  .: 

it 

Calor- 
ies. 
4.27 
4.37 
4.27 

Digestible 
nutrients. 

Total  nu- 
trients. 

Digestible 
nutrients. 

gjj 

Digestible 
nutrients. 

~  >•— 
=  w  '3 

c  £  5 
£ 

Meat  and  fish 

Per 
cent. 
43 
6 
12 

61 

Per 
cent. 
97 
97 
97 

Calor- 
ies. 
4.40 
4.50 
4.40 

4.40 

4.55 
4.45 

Per 
cent. 

32 

Per 
cent. 

95 
95 

Calor- 
ies. 

9.03 

8.79 

Calor- 
ies. 

9.50 
9.25 

Per 
cent. 

Per 
cent. 

98 

Calor- 
ies. 

3.82 

Calor- 
ics. 

3.90 

Pter 

cent. 
87 
89 
93 

89 

91 
83 
98 
98 
91 
88 

Eggs  

Dairy  products  

Animal   food 
(of    mixed 
diet)  

97 

4.27 

92 

95 

8.93 

9.40 

5 

98 

3.82 

3.90 

Cereals  

31 
'      2 

85 
78 

3.87 
3.47 

8 

90 

8.37 

9.30 

55 
1 
1     21 

5 

98 
97 
98 
98 
95 
90 

4.11 
4.07 
3.87 
4.11 
3.99 
3.60 

4.20 
4.20 
3.95 
4.20 
4.20 
4.00 

Legumes  (dried)  ... 
Sugars 

Vegetables  

5         83 
1         85 

3.11 
3.36 

3.75 
3.95 

Fruit                    

.     Vegetable 
food    (of 
mixeddiet). 

Total  food  (of 
mixeddiet). 

39 

85 

3.74 

4.40 

8 

90 

f.  37 

9.30 

95 

97 

4.03 

4.15 

92 

100 

92 

4.05 

4.40 

100 

95     8.93 

9.40 

100 

97 

4.03 

4.15 

91 

Briefly  stated,  on  an  average  about  96  per  cent  of  the  total  organic 
matter  of  mixed  diet  will -be  digested  and  91  per  cent  of  the  energy  will 
be  available  to  the  bod}-;  or,  in  other  words,  the  bod}r  rejects  about  4 
per  cent  of  the  nutrients  and  about  9  per  cent  of  the  energy  supplied 
by  the  food.- 

\Vith  the  exception  of  some  important  European  determinations  of 
heats  of  combustion,  the  figures  given  in  the  above  table  are  derived 
from  late  investigations  in  the  United  States.  These  included  over 
4,500  analyses  of  food  materials;  over  500  dietary  studies;  nearly  600 
digestion  experiments,  mostl}7  with  men;  several  thousand  determina- 
tions of  heat  of  combustion  of  f  ood  materials  and.  excretory  products,  and 
64  experiments,  covering  in  the  aggregate  184  days,  with  men  in  the 
respiration  calorimeter,  besides  a  considerable  number  of  other  experi- 
mental inquiries,  including  especially  the  determinations  of  the  con- 
stitution of  protein  compounds  in  various  materials.  The  results  of 
computations  by  means  of  these  factors  have  been  found  to  agree  very 
closely  with  those  obtained  in  actual  experiments,  showing  that  the 
factors  are  reasonably  accurate. 

THE  PECUNIARY  ECONOMY  OF  FOOD. 

The  sum  expended  for  food  is  the  principal  item  in  the  living 
expenses  of  a  large  majority  of  families,  and  yet  very  few  of  even  the 
most  intelligent  housekeepers  have  clear  ideas  regarding  the  actual 
nutritive  value  of  different  food  materials.  Very  generally,  even  those 
who  endeavor  to  economize  know  little  of  the  combinations  which  are 
best  fitted  for  nourishment  Jind  have  still  less  information  as  to  the1 


U.  S.  Dept.  of  Agr.,  Office  of  Expt.  Stations,  713 


PLATE  VI. 


Protein.  fats  Carbohydrates         Fuel  Value. 


FOOD  MATERIALS 


Price 
per 

pound 


£$/s. 


Pounds  of  nutrients  an<L  -calories  of  fiul  value  m  foments 


Ms 


2000  Cat  woaCal. 


eoooCai 


20 


10 


i*»; 


S^q-g ,  2t  cc/ivte>  ,<&%)! 


S.&5 


2* 


e^-m^o£ 


2.50 


j'vv, 


10.00 


PECUNIARY  ECONOMY  OF  FOOD.    AMOUNTS  OF  ACTUALLY  NUTRITIVE  INGREDIENTS 
OBTAINED  IN  DIFFERENT  FOOD  MATERIALS  FOR  10  CENTS. 

Amounts  of  nutrients  in  pounds;  fuel  value  in  calories. 


19     y.^jv,   *  :*:> 

relation  between  the  true  nutritive  val'ae.crf.  fpo&$'£ri<l  jji&ijfGpSt.  Of 
the  different  food  materials  which  are  palatable,  nutritious,  aha  other- 
wise suited  for  nourishment,  the  consumer  wishes  to  know  what  ones 
are  pecuniarily  the  most  economical;  in  other  words,  which  foods  fur- 
nish the  largest  amounts  of  available  nutrients  at  the  lowest  cost.  In 
answering  this  question  it  is  necessary  to  take  into  account  not  only 
the  prices  per  pound,  quart,  or  bushel  of  the  different  materials,  but 
also  the  kinds  and  amounts  of  the  actual  nutrients  they  contain  and 
their  fitness  to  meet  the  demands  of  the  body  for  nourishment.  The 
cheapest  food  is  that  which  supplies  the  most  nutriment  for  the  least 
mone}7.  The  most  economical  food  is  that  which  is  cheapest  and  at  the 
same  time  best  adapted  to  the  needs  of  the  user. 

In  many  of  the  nutrition  investigations,  especially  the  dietaiy  stud- 
ies carried  on  by  this  Department,  the  cost  of  food  in  relation  to  the 
nutrients  furnished  has  been  considered.  Plate  VI,  which  compares 
a  number  of  common  foods  from  a  pecunia^  standpoint,  shows  tfcie 
amounts  of  the  protein,  fat,  carbohydrates,  and  energy  which  10  cents 
worth  of  each  of  the  food  materials  selected  will  supply.  In  ever}T 
case  the  assumed  price  per  pound  is  an  average  value  based  upon  a 
considerable  amount  of  data  collected  in  different  localities. 

THE  EDUCATIONAL  INFLUENCE  OF  THE  NUTRITION  INVESTIGA- 
TIONS. 

If  the  practical  usefulness  of  these  investigations  is  important,  the 
educational  influence  is  no  less  so.  This  is  manifesting  itself  in  a  num- 
ber of  ways,  but  most  of  all  in  bringing  the  results  of  the  inquiry 
directly  into  schools.  Taking  all  the  public  schools  and  the  colleges 
in  the  county  together,  the  number  in  which  the  results  of  these 
inquiries  are  being  directly  taught  is  relatively  small.  Nevertheless, 
the  actual  number  of  institutions  in  which  teachers  are  including  more 
or  less  of  these  results  in  their  courses  of  instruction,  especially  in  phys- 
iolog}T,  is  numerically  large  and  is  growing  with  the  most  encouraging 
rapidity.  It  has  been  the  policy  of  the  Department  to  deal  very  gen- 
erously with  schools  and  with  teachers  in  the  distribution  of  nutrition 
publications.  Not  only  in  cities,  but  in  rural  districts,  there  is  a  large 
and  rapidly  growing  demand  from  the  schools  for  these  publications. 
They  appear  to  meet  an  actual  want — one  that  has  been  rather  dimly 
felt  hitherto,  but  is  now  becoming  much  more  definite.  The  most  active 
call,  as  would  naturally  be  expected,  has  been  from  teachers  connected 
with  technical  schools  or  the  technical  departments  of  colleges  and 
high  schools.  The  demand,  however,  has  been  almost  as  great  from 
schools  of  medicine. 

That  the  time  for  the  development  of  these  inquiries  is  especially 
opportune  is  shown  by  the  use  made  of  the  results  in  the  teaching  of 
what  is  called  domestic  economy,  or  household  economics.  This  rep- 
resents an  educational  movement  of  greater  import  than  many  realize. 


20 

- 

The  mo^em^Ht;igx59toiing  i.n  response  to  popular  demand  and  1ms  the 
earnest  support  of  iflftiydf*our  leading  educators,  not  a  few  of.  whom 
are  emphatic  in  the  expression  of  their  belief  in  the  wisdom  of  the 
popular  demand  and  the  possibility  of  making  such  instruction  very 
useful,  especially  in  courses  for  girls  and  young  women.  Educational 
experience  shows  that  a  certain  time  is  required  to  bring  any  now 
subject  first  into  scientific  and  then  into  pedagogic  form.  The  science 
of  food  and  nutrition  has  already  assumed  reasonably  clear  and  accu- 
rate scientific  form  and  is  being  rapidl}T  brought  into  pedagogic  form, 

CONCLUSION. 

One  most  important  feature  of  these  investigations  is  the  coopera- 
tion with  scientific,  educational,  and  philanthropic  institutions  in  .so 
many  parts  of  the  country.  Among  the  advantages  of  this  method  of 
cooperation  several  are  especially  worthy  of  mention.  First,  there  is 
the  larger  economy  and  effectiveness  of  scientific  efforts  shown  in  the 
development  of  special  methods  of  investigation,  in  the  planning  of 
general  and  special  lines  of  inquiry,  and  in  the  comparison  and  publi- 
cation of  results.  The  cooperating  investigators  and  institutions  are 
contributors  to  the  enterprise,  and  the  spirit  of  cooperation  thus 
becomes  in  itself  an  important  agency  for  diffusing  the  results  and 
insuring  their  most  useful  application.  Another  advantage  is  found 
in  the  fact  that,  while  institutions  and  investigators  have  that  liberty 
of  initiative  and  action  which  is  so  essential  for  scientific  research,  the 
several  inquiries  are  so  coordinated,  and  investigators  are  so  aided  by 
counsel  and  by  the  collating  of  the  results  of  inquiry  elsewhere  as  to 
give  both  the  individual  investigations  and  the  research  as  a  whole 
far  more  influence  and  usefulness  than  would  otherwise  be  possible. 
From  the  practical  standpoint  also  there  is  an  advantage  in  the  fact 
that  so  many  different  institutions,  representing  the  varied  interests 
of  people  in  widely  separate  regions,  are  united  in  the  study  of  preva- 
lent conditions  and  in  efforts  toward  improvement.  Besides  this  the 
funds  provided  by  the  Department  are  used  economically  and  are 
supplemented  by  the  resources  of  the  institutions  and  often  by  means 
from  other  sources.  Thus  not  only  is  a  large  amount  of  work  being 
done,  but  the  interest  is  widely  extended  and  the  results  are  given 
very  great  practical  usefulness. 

So  it  has  come  about  that  from  modest  beginnings,  in  which  work 
was  carried  on  largely  with  the  aid  of  private  individuals,  these  inves- 
tigations under  the  auspices  of  this  Department  have  assumed  a  mag- 
nitude quite  out  of  proportion  to  their  actual  cost;  have  achieved  a 
noteworthy  significance  in  scientific,  educational,  sociological,  and 
economic  results;  and  by  the  extensive  cooperation  of  individuals  ami 
institutions  of  various  kinds  with  this  Department  a  large  amount  of 
valuable  work  is  being  done  in  a  systematic  way,  the  results  of  which 
are  made  available  to  the  public. 

O 


LIST  OF  PUBLICATIONS  OF  THE  OFFICE  OF  EXPERIMENT  STATIONS  ON 
THE  FOOD  AND  NUTRITION  OF  MAN-Continued. 

Bui.    89.  Experiments  on  the  Effect of  Muscular  Work  upon  the  Digestibility  :  the  Metab- 

olism  of  Nitrogen.    Conducted  at  the  University  of  Tennessee,  1897-1899.    By  C.  E.  Wait, 

]';>.  77.     Price,  5  cents. 
Bui.    91.  Nutrition  I n ventilations  at  the  University  of  Illinois,  North -Dakota  Agricultural  c< 

and  Lake  Erie  College,  Ohio,  1890-1900.    By  H.  S.  Grindley  and  J.  I..  Sammis,  E.  F.  Lodd, 

and  Isabel  Bevier  and  Elizabeth  C.  Sprague.     Pp.  42.     Price,  5  cents. 

Bui.    98.  The  Effect  of  Severe  and  Prolonged  Muscular  Work  on  Food  Consumption,  Digestion,  and 
••  ilism,  by  W.  O.  Atwater  and  H.  C.  Sherman,  and  the  Mechanical  Work  and  Efficiency 

of  Bicyclers,  by  R.  C.  Carpenter.     Pp.  67.     Price,  5  cents. 
Bnl.  101.  Studies  on  Bread  and  Bread  Making  at  the  University  of  Minnesota  in  1899  and  1900.     By 

Harry  Snyder.     Pp.  05.     Price,  5  cents. 
Bnl.  102.  Experiments  on  Losses  in  Cooking  Meat,  1898-1900.     By  H.  S.  Grindley,  with  the  c. 

tioii  of  IJ.  McCormack  and  H.  C.  Porter.     Pp.  (it.     Price,  5  cents. 
Bui.  107.  Nutrition  Investigations  among   Fruitarians  and  Chinese  at  the  California  Agricultural 

Experiment  Station,  1899-1901.     By  M.  E.  Jaffa,     Pp.  43.     Price,  5  cents. 
Bui.  109.  Experiments  on  the  Metabolism  of 'Matter  and  Energy  in  the  Human  Body,  1898-1900.     By 

W.  C).  Atwater  and  F.  G.  Benedict,  with  the  cooperation  of  A.  P.  Bryant,  A.  W.  Smith  and 

J.  F.  Snell.    Pp.  147.     Price,  10  cents. 
Bnl.  116.  Dietary  Studies  in  New  York  City  in  1896  and  1897.     By  W.  O.  Atwater  and  A.  P.  Bryant. 

Pp.  S3.     Price,  5  cents. 

Bui.  117.  Experiments  on  the  Effect  of  Muscular  Work  upon  the  Digestibility  of  Food  and  the  Metab- 
olism of  Nitrogen.    Conducted  at  the  University  of  Tennessee,  1899-1900.     By  C.  E.  Wait. 

Pp.  43.     Price,  5  cents. 
Bui.  121.  Experiments  on  the  Metabolism  of  Nitrogen,  Sulphur,  and  Phosphorus  in  the  Human 

Organism.     By  II.  C.  Sherman.     Pp.47.     Price,  5  cents. 
Bnl.  126.  Studies  on  the  Digestibility  and  Nutritive  Value  of  Bread  at  the  University  of  Minnesota  in 

1900-1902.     By  Harry  Snyder.    Pp.52.     Price,  5  cents. 
Bui.  129.  Dietary  Studies  in  Boston  and  Springfield,  Mass.,  Philadelphia,  Pa,,  and  Chicago,  111.     By 

Lydia  Southard,  Ellen    H.  Richards,  Susannah  Usher,  Bertha  M.  Terrill,  and    Amelia 

Shapleigh.     Edited  by  R.  D.  Milner.    Pp.  103.    Price,  10  cents. 
Bui.  132.  Further    Investigations    among   Fruitarians  at    the  California  Agricultural   Experiment 

Station.    By  M.  E.  Jaffa.     Pp.81.     Price,  5  cents. 
Bui.  130.  Experiments  on  the  Metabolism  of  Matter  and  Energy  in  the  Human  Body,  1900-1902.     By 

W.  ( ).  Atwater  and  F.  A.  Benedict,  with  the  cooperation  of  A.  P.  Bryant,  R.  D.  Milner  and 

Paul  Merrill.     Pp.357.     Price,  20  cents. 
Bui.  111.  Experiments   on  Losses  in  Cooking  Meat,   1900-1903.    By  H.  S.  Grindley  and  Timothy 

Mojonnier.     Pp.  95.     Price,  5  cents. 

Bui.  1 13.  Studies  on  the  Digestibility  and  Nutritive  Value  of  Bread  ?t  the  Maine  Agricultural  Experi- 
ment Station,  1899-1903.     By  C.  D.  Woods  and  L.  II.  Merrill.     Pp.  77.     Price,  5  cents. 

FARMERS'    BULLETINS. 

*Bnl.  23.  Foods:  Nutritive  Value  and  Cost.    By  W.  0.  Atwater.    Pp.  32.   , 

Bui.    31.  Meats:  Composition  and  Cooking.     By  C.  D.  Woods.     Pp.29. 

Bui.    71.  Milk  ns  Food.     Pp.  39. 

Bui.    sr>.  Fish  as  Food.    By  C.  F.  Langworthy.     Pp.30. 

Kul.    93.  Sugar  as  Food.     By  Mary  H.  Abel.     Pp.  27. 

Bui.  112.  Bread  and  the  Principles  of  Bread  Making.    By  Helen  W.  Atwater.     Pp.  39. 

Bui.  121.  Beans,  Pens,  and  other  Legumes  as  Food.     By  Mary  II.  Abel.     Pp.32. 

Bui.  128.  Eggs  and  their  Uses  as  Food.     By  C.  F.  Langworthy.     Pp.  32. 

Bui.  112.  Principles  of  Nutrition  and  Nutritive  Value  of  Food.     By  W.  O.  Atwater.     Pp.  48. 

Bui.  182.  Poultry  as  Food.    By  Helen  Atwater.    Pp.  40. 


Cir.    46.  The  Functions  and  Uses  of  Food.    By  C.  F.  Langworthy.    Pp.  10. 

SEPARATES. 

*Food  and  Diet.    By  W.  O.  Atwater.    Reprinted  from  Yearbook  of  Department  of  Agriculture  for 

1S94.     Pp.44. 
Some  Results  of  Dietary  Studies  in  the  United  States.    By  A.  P.  Bryant,    Reprinted  from  Yearbook 

of  Department  of  Agriculture  for  1X98.     Pp.  14. 
Development  of  the  Nutrition  Investigations  of  the  Department  of  Agriculture.     By  A.  C.  True  and 

R.  D.  Milner.     Reprinted  from  Yearbook  of  Department  of  Agriculture  for  1899.     Pp.  16. 
The  Value  of  Potatoes  as  Food.     By  C.  F.  Langworthv.    Reprinted  from  Yearbook  of  Department  of 

Agriculture  for  1900.     Pp.  16. 
Dietaries  in  Public  Institutions.    By  W.  O.  Atwater.    Reprinted  from  Yearbook  of  Department  of 

Agriculture  for  1891.     Pp.  18. 
The  Cost  of  Food  as  Related  to  its  Nutritive  Value.    By  R.  D.  Milner.    Reprinted  from  Yearbook  of 

Department  of  Agriculture  for  1902.     Pp.  19. 
Scope  and  Results  of  the  Nutrition  Investigations  of  the  Office  of  Experiment  Stations      Reprinted 

from  Annual  Report  of  the  Office  of  Experiment  Stations  for  the  year  ended  June  30,  1901. 

Pp.  50. 
Dietary  Studies  of  Groups,  Especially  in  Public  Institutions.    'By  C.  F.  Langworthy.     Reprinted  from 

Annual  Report  of  the  Office  of  Experiment  Stations  for  the  year  ended  June  30    l'«v> 

Pp.  34. 


sr 'I, ' 


UNIVEESITY   OF   CALIFORNIA   LIBRARY, 
BERKELEY 

THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED   BELOW 

Books  not  returned  on  time  are  subject  to  a  fine  of 
50c  per  volume  after  the  third  day  overdue,  increasing 
to  $1.00  per  volume  after  the  sixth  day.  Books  not  in 
demand  may  be  renewed  if  application  is  made  before 
expiration  of  loan  period. 


1932 


«* 


OCT  7  1946  ^ 


JUN  2  0  186? 


;EP  2  2  1967 


75m-7,'30 


337240 


I 

+ 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


